Next Article in Journal
Improved Efficiency of Perovskite Solar Cells by the Interfacial Modification of the Active Layer
Next Article in Special Issue
Enhanced Light Extraction of Flip-Chip Mini-LEDs with Prism-Structured Sidewall
Previous Article in Journal
Correlation Between Composition and Electrodynamics Properties in Nanocomposites Based on Hard/Soft Ferrimagnetics with Strong Exchange Coupling
Previous Article in Special Issue
Arrayed CdTeMicrodots and Their Enhanced Photodetectivity via Piezo-Phototronic Effect
Article Menu
Issue 2 (February) cover image

Export Article

Open AccessArticle
Nanomaterials 2019, 9(2), 203; https://doi.org/10.3390/nano9020203

Improvement in Light Output of Ultraviolet Light-Emitting Diodes with Patterned Double-Layer ITO by Laser Direct Writing

1,2
,
1,2
,
1,2
,
1,2
,
1,2
and
1,2,3,*
1
Key Laboratory of Hydraulic Machinery Transients (Wuhan University), Ministry of Education, Wuhan 430072, China
2
Center for Photonics and Semiconductors, School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China
3
State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
*
Author to whom correspondence should be addressed.
Received: 7 January 2019 / Revised: 30 January 2019 / Accepted: 30 January 2019 / Published: 4 February 2019
(This article belongs to the Special Issue Optoelectronic Nanodevices)
Full-Text   |   PDF [3485 KB, uploaded 4 February 2019]   |  

Abstract

A patterned double-layer indium-tin oxide (ITO), including the first unpatterned ITO layer serving as current spreading and the second patterned ITO layer serving as light extracting, was applied to obtain uniform current spreading and high light extraction efficiency (LEE) of GaN-based ultraviolet (UV) light-emitting diodes (LEDs). Periodic pinhole patterns were formed on the second ITO layer by laser direct writing to increase the LEE of UV LED. Effects of interval of pinhole patterns on optical and electrical properties of UV LED with patterned double-layer ITO were studied by numerical simulations and experimental investigations. Due to scattering out of waveguided light trapped inside the GaN film, LEE of UV LED with patterned double-layer ITO was improved as compared to UV LED with planar double-layer ITO. As interval of pinhole patterns decreased, the light output power (LOP) of UV LED with patterned double-layer ITO increased. In addition, UV LED with patterned double-layer ITO exhibited a slight degradation of current spreading as compared to the UV LED with a planar double-layer ITO. The forward voltage of UV LED with patterned double-layer ITO increased as the interval of pinhole patterns decreased. View Full-Text
Keywords: UV LEDs; double-layer ITO; pinhole pattern; current spreading; light output power UV LEDs; double-layer ITO; pinhole pattern; current spreading; light output power
Figures

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Zhao, J.; Ding, X.; Miao, J.; Hu, J.; Wan, H.; Zhou, S. Improvement in Light Output of Ultraviolet Light-Emitting Diodes with Patterned Double-Layer ITO by Laser Direct Writing. Nanomaterials 2019, 9, 203.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Nanomaterials EISSN 2079-4991 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top